export default {
	namespaced: true,
	
	state: {
		// 购物车的数组，用来存储购物车中每个商品的信息对象
		// 每个商品的信息对象，都包含如下6个属性
		// {goods_id, goods_name, goods_price, goods_count, goods_small_logo, goods_state}
		cart: JSON.parse(uni.getStorageSync('cart') || '[]')
	},
	
	mutations: {
		ADDTOCART(state, goods) {
			const findResult = state.cart.find(item => item.goods_id == goods.goods_id)
			
			if (!findResult) {
				state.cart.push(goods)
			} else {
				findResult.goods_count++
			}
			
			this.commit('m_cart/SAVETOSTORAGE')
		},
		
		SAVETOSTORAGE(state) {
			uni.setStorageSync('cart', JSON.stringify(state.cart))
		},
		
		// 更新购物车中商品的勾选状态
		updateGoodsState(state, goods) {
			const findResult = state.cart.find(item => item.goods_id === goods.goods_id)
			
			if (findResult) {
				findResult.goods_state = goods.goods_state
			}
			
			this.commit('m_cart/SAVETOSTORAGE')
		},
		
		// 更新商品的数量
		updateGoodsCount(state, goods) {
			const findResult = state.cart.find(item => item.goods_id === goods.goods_id)
			
			if (findResult) {
				findResult.goods_count = goods.goods_count
			}
			
			this.commit('m_cart/SAVETOSTORAGE')
		},
		
		// 根据Id删除对应的商品
		removeGoodsById(state, goods_id) {
			state.cart = state.cart.filter(item => item.goods_id !== goods_id)
			
			this.commit('m_cart/SAVETOSTORAGE')
		},
		
		// 更新购物车中所有商品的勾选状态
		updateAllGoodsState(state, newState) {
			state.cart.forEach(item => item.goods_state = newState)
			
			this.commit('m_cart/SAVETOSTORAGE')
		}
	},
	
	getters: {
		// 购物车中所有商品的总数量
		total(state) {
			return state.cart.reduce((prev, item) => {
				return prev + item.goods_count 
			}, 0)
		},
		// 购物车中已勾选商品的总数量
		checkedCount(state) {
			return state.cart.filter(item => item.goods_state).reduce((prev, item) => prev + item.goods_count, 0)
		},
		// 已勾选商品的总价格
		checkedGoodsAmount(state) {
			return state.cart.filter(item => item.goods_state).reduce((prev, item) => prev + item.goods_count * item.goods_price, 0).toFixed(2)
		}
	}
}